I think this is SOOOOOOO cool. It's called "wedding graffiti" and it's vinyl lettering that you can put on the walls (or various surfaces), but it looks like it's been painted on. What a neat idea for church doors, dance floors, and boring old walls that you want to jazz up. The great thing about it is that you can remove it really easily and it won't damage your walls or surface.

Here's the website for more pics and examples.

http://www.wonderfulgraffitiwedding.com/index.html